Columbite-(Fe)
Columbite-(Fe) is a mineral that is fairly common rarely available as a faceted gem mostly since it is opaque black to brownish black. However, it could be somewhat attractive having its vitreous to luster that is sub-metallic when its surfaces tarnish and become iredescent. Columbite-(Fe) is relatively hard with a Mohs hardness of 6.0 and really dense. It’s another of the gems that are black collectors associated with the uncommon.
Columbite-(Fe) was originally named Columbite (without the suffix that is-Fe in 1805 by Scottish naturalist and mineralogist Robert Jameson (1774-1854) for its columbium content. The element columbium (Cb) had been found and named in 1801 by English chemist Charles Hatchett (1765–1847) after Columbia, the historic and poetical name for America, where it absolutely was discovered that is first. The title Columbia was derived from, as well as in honor of, Christopher Columbus, discoverer of America. Columbium was the original, but now obsolete, name of the element niobium (Nb). Columbium ended up being “rediscovered” in 1844 by German chemist Heinrich Rose (1795-1864) who named it niobium from the Greek figure that is mythological, a daughter of Tantalus, and the Greek symbol of eternal mourning. The element columbium (Cb) was eventually assigned the genuine name niobium (Nb) in 1950 by the Global Union of Pure and Applied Chemistry (IUPAC).
The mineral Columbite was renamed Ferrocolumbite in 1844 by United states mineralogist Charles Upham Shepard (1804-1886) because of its iron that is ferrous) content. Ferrocolumbite was eventually renamed Fe that is columbite the IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) in September, 2007 (proposal IMA 07-C) and posted in articles entitled “Tidying up Mineral Names: an IMA-CNMNC Scheme for Suffixes, Hyphens and Diacritical Marks” in the Mineralogical Record, vol. 39, No. 2, pages 131-135 (March – April, 2008).
A mineral with the chemical that is identical to Columbite ended up being named Niobite in 1845 by Austrian mineralogist Wilhelm Karl Ritter von Haidinger (1795-1871) for its niobium (Nb) content. But the Columbite name had precedence that is historic continues to be to today. So, even though the name of the element which inspired the name Columbite was changed from columbium to niobium, the mineral name remains Columbite and the name Niobite, which was encouraged by the name that is current of element, was abandoned. Get figure.
Circulation of Columbite-(Fe): in the united states, in Connecticut, at Middletown, Portland, and Haddam, Middlesex County; big masses from the Beecher Lode, eight km southeast of Custer, Custer County, and around Keystone, Pennington County, Southern Dakota; in the Spruce Pine district, Mitchell County, and the Foote mine, Kings Mountain, Cleveland County, North Carolina. At Ånneröd, Tveit, and somewhere else in Norway. In Russia, from Miass, Ilmen Mountains, Southern Ural Mountains. At Craveggia, Val Vigezzo, Piedmont, Italy. Large crystals from Ambatofotsikely and Antsirabe, Madagascar. At Greens Well, Wodgina, Greenbushes, and elsewhere in Western Australia. In the Ishikawa district, Fukushima Prefecture, Japan.
| Category: | Oxide minerals |
| Chemical Formula: | Fe2+Nb2O6 |
| Iron Niobium Oxide | |
| Molecular Weight: | 337.66 gm |
| Composition: | Niobium | 55.03 % | Nb | 78.72 % | Nb2O5 |
| Iron | 16.54 % | Fe | 21.28 % | FeO | |
| Oxygen | 28.43 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Orthorhombic – Dipyramidal |
| Crystal Habit: | Crystals short prismatic or equant, also flat tabular, to 0.75 m. In groups of parallel or subparallel crystals, to 18 t; massive. |
| Twinning: | Common as heart-shaped contact and penetration twins, on {021} and {023}, may produce pseudohexagonal trillings. More rarely on {051} and {15•1•0}. |
| Cleavage: | Distinct on {100}, less distinct on {010}. |
| Fracture: | Irregular/uneven, sub-conchoidal |
| Tenacity: | Brittle |
| Mohs Hardness: | 6.0; VHN = 652-739 (100 g load) |
| Density: | 5.20 – 6.65 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Other: | Paramagnetic |
| Color: | Black to brownish black. Reddish brown in transmitted light. |
| Transparency: | Opaque |
| Luster: | Vitreous, sub-metallic; commonly tarnishes to iridescent |
| Refractive Index: | Biaxial ( – ); R1–R2: (400) 18.4–19.1, (420) 17.7–18.6, (440) 17.3–18.2, (460) 17.1–17.9, (480) 16.9–17.7, (500) 16.9–17.6, (520) 16.8–17.5, (540) 16.8–17.4, (560) 16.7–17.3, (580) 16.7–17.2, (600) 16.7–17.2, (620) 16.6–17.1, (640) 16.5–17.1, (660) 16.4–16.9, (680) 16.3–16.8, (700) 16.1–16.8 |
| Birefringence: | 0.000 (opaque) |
| Dispersion: | r < v |
| Pleochroism: | None |
| Anisotrophism: | In reflected light: grayish white with a brownish tint and reddish internal reflections. |
